Peripheral nerve injuries (PNI) are severely debilitating, affecting otherwise healthy patients by limiting their ability to perform activities of daily living. Peripheral nerve injuries may result from various etiologies, from complex trauma to iatrogenic and compressive neuropathies. However, despite various etiologies the mainstay to repair peripheral nerve damage is surgical repair of transected nerve ends or surgical release of compressed nerves. Unfortunately, even the best surgical procedures usually leave patients with marked deficits. Given the disability associated with PNI, a need clearly exists to improve outcomes.
Currently, clinical treatment of injured peripheral nerves is primarily surgical, either releasing the source of nerve compression or reattaching the transected nerve directly or with grafting materials. Surgery permits nerve regrowth by re-establishing nerve continuity but functional recovery remains inadequate. Generally, nerves regenerate slowly (˜1 mm/day at their fastest) requiring long periods of time before reconnecting with denervated target muscle or sensory end-organs. The window of opportunity for nerve regeneration is short with the regenerative capacity of the injured neurons and the regenerative support of the distal nerve stump declining with time and distance. These factors together with the misdirection of regenerating nerves account for the frequent poor recovery.